Means for operating electric-arc lamps.



No. s3|,975. Patented Aug.'29, I899. H. A. WAGNER & n. w. ROPER.

MEANS FOR OPERATING ELECTRIC ARC LAMPS.

(Application filed May 25, 1899.) No Model.) 2 Sheets-Sheet I,

5440mm) H. A. Wagner 5514 aflo'amu R0 per flaw m: NORll$ mus ca. monnrmN0. 63!,975. Patented Aug. 29, I899. H. A. WAGNER & D. W. BUPEB.

MEANS FOR OPERATING ELECTRIC ARC LAMPS.

(Application filed May 25, 1899.)

(No Model.) 2- Sheets-Sheet 2.

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UNITED STATES PATENT OFFIC HERBERT A. \VAGNER AND DENNEY W. ROPER, OFST. LOUIS, MISSOURI.

MEANS FOR OPERATINQ ELECTRIC-ARC LAMPS.

SPECIFICATION forming part Of Letters Patent N0. 631,975, dated August29, 1899. Application filed May 25, 1899. Serial No. 718,162. (Nomodel.)

To LY/ZZ whmn it may concern:

Be it known that we, HERBERT A. WAGNER and DENNEY VV.ROPER, citizens ofthe United States of America, residing at St. Louis, in the State ofMissouri, have invented a certain new and useful Method of and Means forOperating Electric-Arc Lamps, of which the following is such a full,clear, and exact description as will enable any one skilled in the artto which it appertains to make and use the same, reference being had tothe accompanying drawings, forming part of this specification.

This invention relates to a method of and means for operatingelectric-arc lamps on constant-potential circuits or circuits derivedfrom a constant-potential source, whereby the efliciency of distributionis increased and the cost of operation reduced.

Vhen an arc-lamp circuit is open and no current is passing the carbonsare in contact and the resistance of the circuit including the lamp isonly a small fraction of that of the same circuit when the lamp is innormal operation. At the instant of closing the lampcircuit the fullvoltage of a constant-potential source applied to the low-resistancelampcircuit causes a sudden rush of current through the lamp-circuit farabove the normal, and this passing through the controlling solenoiddraws the carbons violently and suddenly apart. This action is so rapidthat the carbon vapors, upon whose existence the arc is dependent, donot have time to form and the arc is broken. This interrupts the circuitand prevents the flow of current which energizes the controlling-magnet,and the carbons coming together again the action is repeated many times,causing chattering. This chattering continues until the carbons finallybecome heated by the action of the current and an arc is struck. Thechatteringis especially violent with differential lamps, as at theinstant of rupturing the arc the full strength of the shunt-coilsassists the weight of the moving parts in bringing the carbons together.This chattering is very annoying to the user of the lamp and destructiveto the lamp mech-- anism. This chattering may be reduced in severalways. A quiet start may, if other conditions are favorable, be obtainedby us- These carbons are,

ing soft-cored carbons.

however, expensive and short-lived. Another method of overcoming thischattering is to use dash-pots to restrain the upward movements of thecontrolling-magnet; but if these dashpots are sufiiciently strong tostop the chattering they necessitate the maintenance of an excessivecurrent in the lamp-circuit. Still another method of preventing suchchatter ing consists in using a fixed resistance kept continually in thelamp-circuit. This latter prevents excessive current therein and is avery effective method of reducing the chattering at the start, but theoperating efficiency is very low, as the resistance required for smoothoperation is considerably less than that necessary for a quiet start.Our method of overcoming this difficulty secures a quiet start withoutallowing the current at starting to exceed the normal withoutsacrificing the efficiency of the lamp during operation, and permits theuse of harder, less expensive, and longer-lived carbons.

\Ve have found that if the carbon-tips are first heated to redness inany suitable way,

as by a current too weak to lift the carbons,

su fiicient carbon-vapor will be formed to maintain the are when thenormal current is applied to the lamp, and our invention relates to thismethod of preparing the carbons for starting the arc and means foraccomplishing the same, whereby a distinct separation of the startingand operating conditions is secured. By the first step of our method thecarbon-tips are heated by a reduced current insufficient to causechattering. The next step of our method consists in altering theconnections or arrangement of the lamp-circuit so as to remove theresistance employed at starting and strike the normal arc. By makingthis total separation of the starting and running conditions we areenabled to make each set of conditions the most favorable for thepurpose instead of compromising on one set of conditions which is notthe best for either starting or for permanent operation.

In the accompanying drawings, illustrating diagrammatically severalforms of our inven tion, Figure 1 shows our invention applied to anumber of arc-lamps operated in series; Fig. 2, the same, but illustrating diagrammatically a transformer for modifying the voltage; Fig.3, our invention as applied to a single arc-lamp operated by directcurrent; Fig. 4, our invention as applied to single arclanips operatedby alternating current; Fig. 5, the same as Fig. but showing a solenoidand dash-pot for automatically cutting out the resistance employed atstarting.

The same marks of reference refer to the same parts throughout thedifferent figures of the drawings.

Having now more particular reference to Fig. 1, M M are theconstant-potential mains. A A A are the arc-lamps. R is astartingresistance, S a switch for short-circuitin g thestarting-resistance, and S a switch for opening the lamp-circuit L. Thisarrangementis equally applicable to direct or alternating current lamps.

Fig. 2 shows our invention as applied to a circuit containing a seriesof alternating-current arc-lamps in which the desired voltage for theseries of lamps is different from that of the constant-potential mains.T is a transformer for making a change in the voltage and may be woundand connected in any desired manner. The starting-resistance I in thisinstance is preferably made inductive.

The ways of applyin g our invention shown in Figs. 1 and 2 are alsoapplicable to a single arc-lamp in cases where the voltage of theconstant-potential source is suitable for a single arc-lamp.

Fig. 3 shows the application of our invention to a single direct-currentarc-lamp operated from mains M M whose voltage is suitable for onearc-lamp, E being the ordinary electromagnetic device for controllingthe arc.

Fig. 4 illustrates the method especially applicable to singlealternating arc-lamps. In this case the inductive starting-resistance Iforms part of an economy transformer or autoconverter T. One end of thelamp-circuit L is connected to the economy-transformer intermediate itsends, and the other end of the lamp-circuit is connected to the lamp.When the switch S is closed and switch S is open, I acts as an inductivestarting-resistance in series with the lamps, as above described. IViththe switch S and the switch S closed, the economy-coil acts in theordinary manner to reduce or transform the voltage of the circuit tothat desired for operating the arclamp. IVhen both switches S and S areopen the apparatus is out of circuit.

Fig. 5 is the same as Fig. 4:, with the addition of a solenoid O forautomatically closing the switch S and a dashpot D for slowing theaction of the solenoid. The solenoid acts to close the switch S as soonas the circuitclosing switch S admits current to the lamp; but thedash-pot retards this action until the carbon-points are suflicientlyheated to permit the arc being started. Any other device with a timeelement in its action may be used instead of the dash-pot and solenoidfor operating the switch S.

The switch S of Figs. '1, 8, and 3 and the switch S of Fig. 4.- maybeoperated in any desired way.

Having fully set forth our invention, what we desire to claim and secureby Letters Patent is- 1. In an elcctricarc-lightiug system, the methodof heating the carbon-tips by a reduced current, and then altering theconnec tions of the circuit to permit the flow of normal current and thenormal operation of the lamp.

2. In a system of electric-arc lighting, the method of first heating thelamp carbon-tips by an electric current insufficient to permit thecarbons to separate, and then suitably varying the current orconnections to allow the carbon-controllin g mechanism to draw the arcand permit the lamp to operate normally.

3. In an electric-arc'lighting system, the method of heating thecarbon-tips by a re duced current and then, without opening the circuit,altering the connections or arrangcment of the circuit so as to allowthe normal current to pass.

a. The method of operating an electric-arclighting system, whichconsists in interpos ing a resistance in the lamp-circuit at starting toreduce the current and thereby heat the carbon-tips without separatingthem, and then, when thetips have been so heated, cutting out the saidresistance to allow the normal current to flow and the arc to be drawn.

5. In a system of electric-arc lighting, means for first heating thelamp carbon-tips with a current insufficient to lift the carbons apart,in combination with means for subsequently increasing the current to thenormal amount required for drawing the arc and operating the lamp orlamps.

6. In an electric-arc-lighting system, the combination of an electriccircuit, an arc lamp or lamps therein, a resistance in said circuit atstarting for reducing the current passing through said lamps to anamount sufficient to heat the carbon-tips to redness but insuflicient todraw the arc, and a switch for cutting out said resistance aft-erstarting to bring the current up to the normal operating amount.

7. In an electric-are-lighting system, the combination of an electriccircuit, an arc lamp or lamps therein, carbon-controlling mechanism, aresistance in said circuit for reducing the current passing through saidlamps, and an electrically-controlled switch and retarding device,whereby said resistance may be automatically shunted at a predeterminedinterval after current is applied.

8. In an electric-arc-lighting system, the combination of an arc-lampwith carbon-com trolling mechanism, a divided transformer coil, alamp-circuit connected therewith, one end of said lamp-circuit beingconnected to said transformer at its point of division, and anelectrically-controllcd slow-acting switch between the other end of saidlamp-circuit and one end of said divided transformer and our hands andaflixed our seals in the presopen at the start, whereby thetransformerenoe of the two subscribing Witnesses.

coil may firstimposeimpedaneein series with HERBERT A. WAGNER. [L. 3.]

the lamp, and at a given interval thereafter DENNEY W. ROPER. [L. s.] 5transform the voltage for the normal opera- Witnesses:

tion of the. lamp. A. O. FOWLER,

In testimony whereof We have hereunto set \V. A. PARKER.

